Guilty of preferring it muddied up a bit.I just listened to both versions back-to-back and I have a couple of observations.
One, Withers' version of the song was very short, and it made for a very straightforward and rather succinct statement. Herb's version is nearly twice as long, but both work very well.
Second, I'm not sure that retaining the minor chords Withers used to accompany those phrases would have served Herb's take on the song quite as well as the major ones did. Herb's take relies heavily on on the lilt that is inherent to the melody, and Withers seems to downplay it, except on the chorus, which is the main hook of his version. Herb utilizes the inherent lilt and emphasizes it with the bass and drums throughout the song. The main reason for the Autotune, IMO is to "punch up" the lyric a bit. The song needs a lyric, I think. Autotune helps it stand up to the plaintive trumpet and the emphasis the bass and drums put on the lilt. Using those minor chords would muddy things up, IMO. They would be difficult to recognize with all that's going on otherwise in the arrangement.
Once again, YMMV.